Rod lift pump systems such as, e.g., beam pump systems, or sucker-rod pump systems, can be used to generate artificial lift to extract liquid from wells. Rod lift pump systems can include a surface pumping unit, which drives a plunger up and down within a barrel positioned within a well to generate artificial lift to extract liquid from the well. One parameter that can affect performance of the rod lift pump systems is pump fillage. Pump fillage can describe an amount of fluid that is within the barrel prior to a downstroke of the plunger. Pump fillage can be expressed as the amount of fluid within the well prior to the downstroke of the plunger, relative to a total amount of fluid that can be extracted based on a stroke length of the plunger. A fillage set point can describe a minimum acceptable pump fillage prior to a downstroke of the plunger. In some cases, if the pump fillage is less than the fillage set point prior to a downstroke of the plunger, the rod lift system can stop or slow pumping to allow the barrel to fill (thereby increasing the pump fillage). Typically, rod lift systems are set to operate with a pump fillage set point that is between 70% and 80%. By adjusting the pump fillage set point, the performance of the rod lift system can be altered. For example, decreasing the pump fillage set point can increase a volume of production from the well, but it can also lead to an increased risk of damaging components of the pump as a result of fluid pound. Fluid pound can occur when the rod lift system operates at less than 100% fillage causing the plunger to strike fluid within the barrel during down stroke.